1221234321221 has 32 divisors (see below), whose sum is σ = 1321410578688. Its totient is φ = 1124475678720.

The previous prime is 1221234321173. The next prime is 1221234321239.

1221234321221 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1221234321221 - 2²⁶ = 1221167212357 is a prime.

It is a super-2 number, since 2×1221234321221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221234321271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 311299166 + ... + 311303088.

It is an arithmetic number, because the mean of its divisors is an integer number (41294080584).

Almost surely, 2^{1221234321221} is an apocalyptic number.

It is an amenable number.

1221234321221 is a deficient number, since it is larger than the sum of its proper divisors (100176257467).

1221234321221 is a wasteful number, since it uses less digits than its factorization.

1221234321221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5981.

The product of its digits is 2304, while the sum is 26.

The spelling of 1221234321221 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-four million, three hundred twenty-one thousand, two hundred twenty-one".